Foreign Object Detection in Food Production with X-Ray

What is

Foreign Object
in Food Industry?

Foreign Object Detection in Food Production with X-Ray

Nowadays food producers have many options when it comes to the detection of foreign objects from food production lines. What are the factors you should focus on when deciding between different inspection systems?

First off, let’s determinate what is a food safety hazard. According to the Food and Drug Administration’s (FDA) “HACCP Principles and Application Guidelines” a hazard (meaning a risk to safe food) is “a biological, chemical, or physical agent that is reasonably likely to cause illness or injury in the absence of its control.”

The foreign object can stay hidden inside the food products. Stainless steel and glass are detected regardless of the metalized packaging material and high salt content.

Physical agents

Physical agents (a.k.a. foreign objects or bodies) are any undesirable, solid objects in food. They can be divided either into hazardous or non-hazardous contaminants.

For example, non-hazardous contaminants such as hairs or paper (although unpleasant) do not possess direct danger or cause injury to the consumer, if found in the food product.

For controlling foreign objects such as these, proper processes should be put in place to avoid initial contamination. These processes can mean the use of appropriate protective clothing and hair nets etc., as well as limiting the use of materials that could contaminate naked products.

Contaminants such as metals, glass, and stones are classified as hazardous foreign objects.

How to Prevent Contaminants?

A proper HACCP plan should be introduced in order to prevent these contaminants from ending up in the finished food product. A good plan will also help food producers manage raw material vendors’ quality and remove foreign objects effectively from the production.

There are requirements in the HACCP standard, that obligate food producers to set up control points with critical limits to ensure that the product safety is on an acceptable level.

Typically, food producers use metal and/or X-ray inspection for foreign object detection in food production as their CCP (Critical Control Points). Both technologies are commonly used, but there are reasons why X-ray inspection is becoming a more popular inspection method.

Foreign objects can vary in size and material. That’s why detection based on density provides the best performance.


There can be massive consequences if contaminated products end up in the hands of consumers. That’s why foreign object detection is the key to protect your customers AND your brand.

There are multiple reasons why contaminated products are bad for the business. They are the main reason for product recalls, loss of brand loyalty, and most importantly they may cause injury to your customers.

To fully prevent contaminations, it is important to know where your foreign objects are coming from. The goal is to find the possible hazards as early as possible in your production process. This is one reason why inspecting large cases just before the shipment is not a very effective practice compared to single packaging inspection.

3 key points you should know about FOD implementation

  1. Identify Potential (Hazardous) Foreign Objects

Identifying the possible and dangerous foreign objects that may present a food safety hazard if not removed before they reach the consumers, is the first step in the HACCP Plan. This should be done also for the raw materials used, and their respective vendors.

  1. Establish Critical Control Points and Critical Limits

There is no one fixed global standard to base the critical limits on, but instead, food producers should conduct proper application tests with the quality control system vendor to determine the performance level on their products, as well as the best placement for the CCP system. There are some guidelines for the critical limits, e.g. many retail chains have their own expectations on the performance for CCPs and FDA has set certain limits for contaminants that may present a choking hazard for a newborn baby.

  1. Implement Inspection System

A well-executed investment process together with the necessary application/product tests, deciding on the critical control point performance limits and defining the best location for the CCP in your production line, ensures that the installation of the quality control system will be effortless and successful.

What to Do After the CCP is Installed?

Once the CCP is installed according to the HACCP Plan, it is important to pay attention to the monitoring, recordkeeping, and corrective actions:

  • Monitoring procedures measure the critical limits at each CCP and should describe how and when the limits are measured, who is responsible for it and how frequently they are measured during the production.
  • Recordkeeping is an important part of a HACCP Plan. It is meant to store the data and provides a good way for food producers to prove that the food was produced safely and according to the set plan.
  • Corrective actions should be established in case of the critical limits set in the HACCP Plan are triggered, i.e. a foreign object is detected in the food production. These actions usually include the identification of the problem (how did the foreign object get into the production) and the steps taken to assure that the problem will not occur again.


As a conclusion, it’s fair to say that HACCP plan and the foreign object detection requirements are often triggers to implementing a quality control system in food production plants. However, it is not an isolated process, instead it becomes a seamless part of the complete production process – resulting in more efficient and higher productivity levels and providing consistent quality food for the consumers.

If an X-ray system is used as the Critical Control Point, food producers get more value from the investment. The X-ray provides features towards a total food quality control that goes beyond inspecting only metallic foreign objects from the production. The complete quality of food products consists of multiple factors such as detecting also non-metallic contaminants, missing products, fill levels, the presence of components in the product, product counting and reporting etc. This broadness of capabilities is one of the main reasons why the X-ray systems are becoming more and more popular choices as Critical Control Points for food factories worldwide!

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